.bash_profile Java/jenv configuration which sets JAVA_HOME dynamically from jenv

.bash_profile

# Java Configuration: jenv, JAVA_HOME, utilities and aliases, etc...
DEFAULT_JAVA_HOME="/Library/Java/JavaVirtualMachines/jdk1.8.0_192.jdk/Contents/Home"
if which jenv > /dev/null
then
  export JENV_ROOT="$HOME/.jenv"
  export PATH="$JENV_ROOT/bin:$PATH"

  # Enable shims and autocompletion.
  # WARNING jenv init wipes out any previously set JAVA_HOME variable.
  eval "$(jenv init -)"

  export JAVA_HOME="$JENV_ROOT/versions/$(cat $JENV_ROOT/version)"
else
  export JAVA_HOME="$DEFAULT_JAVA_HOME"
  echo "WARNING: jenv cannot be found. Setting JAVA_HOME to the hard-coded default: $JAVA_HOME"
fi
alias keytool="$JAVA_HOME/bin/keytool"